Lihir gold mine’s December 2012 quarter performance was 147,126 ounces of gold at a production cash cost of A$649 per ounce, according to Newcrest Mining Ltd’s quarterly report released yesterday.
This compares with the September 2012 quarter performance of 129,311 ounces of gold at a cash cost of A$632 per ounce.
|The new semi-autogenous grinding (SAG) and ball mills at the Lihir mine which are in the final stage of commissioning.|
“Gold production was 14% higher than the September 2012 quarter, associated with a 37% increase in mill throughput partially offset by lower grade and recoveries,” the report said.
“The previous quarter was primarily impacted by a production interruption due to an electrical fault in the main oxygen plant.
“Lower feed grade in the December quarter resulted from a planned transition from Stage 11 of the Lienetz pit into ore from Stage 12 of the Minifie pit.
“Total material movement was 20% higher in the December quarter, comprising both increased ore mined and additional waste stripping in Stage 12 and Stage 9 of the Minifie pit to access future ore sources.”
The report said site costs were higher than the previous quarter as both mining and milling rates increased.
“Unit cash costs were 3% higher than the previous quarter primarily as a result of milling lower grade ore,” it said.
“The progressive increase in production volumes associated with the Million Ounce Plant Upgrade (MOPU) ramp-up is expected to contribute to a reduction in unit costs in the second half of the financial year.
“Refurbishment projects are progressing to plan to improve the older sections of the plant.
“Projects include upgrading the electrical and control systems and replacing the neutralisation cyanidation adsorption (NCA) circuit.
“The expansion project of increasing the flotation capacity is proceeding on schedule to a July 2013 delivery.”
Newcrest is currently undertaking a major expansion of the Lihir process plant, known as the MOPU.
The US$1.4 billion MOPU project, which will be completed by the end of this month, includes installation of a new crushing facility, upgrades to the ore processing plant, and additional power generation capacity and water supply.
This expansion of the processing plant will better match processing rates to mining rates and will increase throughput.
It will provide increased operational flexibility, reduce the exposure to single pieces of equipment and lower fixed costs per tonne, with the medium term objective being to lift annual gold production output to 1.2 million ounces.